The present invention relates, in general, to damper regulators for controlling the flow or air or the like in the ducts of a heating, ventilating or air conditioning (HVAC) system. More particularly, the present invention relates to a damper positioning lock.
It is well-known in ducted heating, ventilating or air conditioning systems to provide, at selected number of points, regulating damper assemblies 20, such as that shown in FIG. 1, for controlling the rate of flow of air or the like through the ducts of the HVAC system. Such known assemblies 20 generally include a blade 22 dimensioned to conform substantially to the cross-section of a flue or duct 24 through which the passage of air or the like is regulated (e.g., a generally circular blade 22 for a generally cross-sectionally circular duct 24). The blade 22 is attached to a shaft 26 which is itself rotatably connected to the duct 24 by bearings such that the blade 22 is pivotable within the duct 24 as the shaft 26 is rotated. One end of the shaft 26 extends out from the duct 24 and through an aperture (not shown) in the hub of a simple handle or lever 28 where the aperture is sized and shaped to engage the shaft 26 (e.g., a generally square aperture for a cross-sectionally square shaft 26). The shaft 26 further extends through an aperture (not shown) of a bracket 30 connected to the exterior of the duct 24 where the shaft 26 is rotatable within the aperture of the bracket 30. A user rotating the lever 28 causes the shaft 26 to rotate within the duct 24, and the blade 22 therewith so that the blade 22 is able to be rotated between configurations where the duct 24 is in an open configuration, allowing air or the like to pass through the duct 24, and where the duct 24 is in a closed configuration, preventing the flow of air or the like from flowing past the blade 22 through the duct 24.
Attempts have been made to improve the ability to fix the blade in a particular orientation within the duct between fully open and fully closed configurations. As seen in FIG. 2, a lever 32 used with a regulating damping assembly, such as the assembly 20 illustrated in FIG. 1, is connected to a plate 34 having a slot 26. The lever 32 is held in any desired radial angular position by means of lever locking mechanism 38 that includes a bolt 40 which passes through the lever 32 and the slot 36. The head (not shown) of the bolt 40 engages one side of the slot 36 and a wing-nut 42 engages the other end of the bolt 40 in order to secure the lever 32 in a locked configuration. Tightening of the wing-nut 42 secures the head of the bolt 40 against the area of the plate 34 surrounding the slot 36, preventing the lever 32 from being able to be moved. Another example of this type of locking mechanism is described in U.S. Pat. No. 1,282,811.
However, conventional positioning locks, such as those described above, have certain disadvantages. For example, the use of the positioning lock is limited by the fact that a user cannot actually see the orientation of the blade within the duct. The use of a conventional positioning lock can result in a user guessing just how far open/closed the duct because the user cannot see the blade as it is being used.
Various attempts have been made to overcome the problems associated with conventional damper positioning locks. For example, U.S. Pat. No. 1,885,548 discloses a damper apparatus. However, this damper regulator is still limited in its ability to lock the lever, and by extension the blade, in an exact position. In another example, U.S. Pat. No. 2,345,997 discloses a dial damper regulator. However, this damper regulator still suffers from the same drawbacks as a wingnut and bolt combination are still used to lock the blade in position. In a further example, U.S. Pat. No. 3,073,564 discloses a damper regulator. However, this damper regulator also uses a wingnut and bolt combination to secure the lever in position and likewise suffers the same drawbacks as discussed above. In a further example, U.S. Pat. No. 5,169,121 discloses a damper control mechanism. However, this device requires the use of a motor and gear unit, a power supply and the like.
Accordingly, there is a need for a damper positioning lock that provides a number of exact locking positions. There is a further need for a damper positioning lock that provides for simple locking/unlocking of the lever. There is an additional need for a damper regulating lock that is simple and economical to manufacture. The present invention fulfills these needs and provides other related advantages.